An AC (alternating current) coupling buffer of an integrated circuit device may be used to receive an AC signal from outside the integrated circuit device and to buffer the signal for use inside the integrated circuit device. An AC coupling buffer, for example, may be used to receive a differential clock signal from outside an integrated circuit memory device and to buffer the differential clock signal for use inside the integrated circuit memory device. More particularly, the buffered differential clock signal may be coupled to input/output buffers of the memory device, and the input/output buffers may be configured to write data to and/or read data from a memory cell array responsive to the buffered differential clock signal.